Mucuna P. (PowerFULL) not only increases endogenous GH, but replenishes levels of other neuropeptides and neurotransmitters as well; most notably, dopamine, and serotonin. This leads to a neurostimulative effect, raising mood, awareness, coordination, and so on. The lack of this 'boost', may be what you are experiencing. However, with that being said, you may want to consult a physician, as the cessation of PowerFULL should not cause depression.